NEW ORLEANS, LA - AUGUST 12: Alex Smith #11 of the San Francisco 49ers is hit by Roman Harper #41 of the New Orleans Saints during a preseason game at Louisiana Superdome on August 12, 2011 in New Orleans, Louisiana.

And they roared, moments later, when wideout Braylon Edwards made a one-handed catch during the same passing drill.

Meanwhile, on the other end of the field, another group of Niners - the offensive linemen - practiced largely unobserved.

Of course, it's not unusual for the guys in the trenches to toil in obscurity.

But after last week's dreadful performance in a 24-3 preseason-opening loss to the Saints, it's safe to say all eyes will be on San Francisco's front five when it returns to Candlestick to host the Raiders on Saturday.

Center Adam Snyder conceded the obvious after the line allowed six sacks against the Saints' relentless blitzing: Such a performance could not be repeated.

"There's no excuse for it," Snyder said. "We just have to get better. A lot of it just comes down to us executing our job."

Snyder said the game left a "bitter taste in his mouth," and it probably left a few bruises on the back of quarterback Alex Smith, who took two vicious blindside hits during San Francisco's first five offensive plays.

So what, exactly, was the problem?

The Niners worked daily on blitz pickups during their first 12 practices. But Smith said they weren't prepared for anything resembling the Saints' hyperaggressive pressure schemes, which typically aren't unleashed in the preseason.

"It was something we hadn't seen a lot of this camp thus far," Smith said. "We had seen it on film, but there are no rules in the preseason. So they decided to bring it out and we've got to get better."

The Niners' offensive line wasn't a huge topic entering the preseason. San Francisco returned four starters, including 2010 first-round picks in left guard Mike Iupati and right tackle Anthony Davis, and replaced center David Baas with Jonathan Goodwin, a pro Bowler with the Saints in 2009.

Their opening act has suddenly made the unit a hot discussion topic, but left tackle Joe Staley believes the talk will subside once the offense, as a whole, begins to communicate better. After Saints defensive end Will Smith got by Staley and leveled Alex Smith, Staley had an animated conversation with Iupati.

"I think, overall, the big thing was communication," Staley said. "We've got to communicate better across the whole offensive line. That includes running backs and tight ends - they are in a lot more on protections now, too. There were too many mental errors, too many mental errors. That was what the big issue on offense was."

Niners coach Jim Harbaugh said the passing game - and blitz pickups - were a big part of Sunday's practice at Candlestick.

When they return to the stadium Saturday, the line hopes to offer a performance that will push them out of the spotlight and back into the shadows.

"Obviously, it's not what we wanted to do on the first week," Staley said. "But we'll get better. I believe in everybody out here. We're all working hard and we're going to make big strides this week and go in the Raider game and perform better."